Thoracic aortic rupture is a type of traumatic aortic injury commonly seen in high-speed motor vehicle collisions¹. In fact, mechanism of injury is considered to be one of the most important factors leading to a diagnosis of aortic rupture³. 

Mechanisms include:

• motor vehicle crashes at speeds >30 mph
• unrestrained drivers
• ejected passengers
• pedestrians struck by motor vehicles
• falls from >10 feet

Pathophysiology of thoracic aortic injury, including aortic rupture, includes the following three causes:

1. Rapid deceleration - this may cause torsion and shearing of the aorta against its fixed segments - particular the aortic root, ligamentum arteriosum and diaphragm
2. Increased intrasvascular pressure - pressures of up to  2000 mmHg may be generated as a result of compression to the aorta which may in turn damage the vessels of the aortic wall
3. Osseous pinch - compression of the aorta between the anterior chest wall and the posterior vertebral column may give rise to aortic injury, as well as subclavian and carotid injury

Since the 1990's, there has been a shift away from open surgical repair of aortic injury. Instead, thoracic endovascular aortic repair (TEVAR) has gradually replaced open repair as the mainstay of operative aortic injury management². It is associated with significantly lower operative times, procedural blood loss and intraoperative blood transfusion compared to open repair.

In this patient, the aortic injury can be best appreciate on the bony coronal views, where the initmal flap is present in the inferior half of the aortic arch.

Case contributed by A/Prof Pramit Phal.